I understand what you are saying, OP, and I pretty much agree with you. I feel the mysteries of our ancient past have just as much to do with physical, three dimensional alien beings as well as other-dimensional angelic beings that are physically (or dimensionally) closer to the Source than ourselves and other third dimension beings.

The Ancient Aliens series is fun to watch, as it brings to light many mysteries of our ancient past. Unfortunately, it also tries to postulate answers from just one side of the coin. Every once in awhile, Erich Von Daniken will briefly speculate the possibility of celestial beings being of God and sometimes uses the word "spiritual", but quickly goes back to physical alien beings with only advanced knowledge of technology. The term "spiritual" is left empty and up to your own vague interpretation.

Tsoukalos would rather you believe that there is no God, no angels and nothing that you could consider spiritual in the highest sense - Only the possibility that some aliens might not have recognizably physical bodies. And while his terminology is somewhat vague and murky and really could be taken in either direction, he leads the viewer in the direction of atheism - or agnosticism at best...ever planting the seeds of doubt in peoples minds.